This is a review and detailed measurements of the dbx 1231 stereo balanced Graphic Equalizer. It is on kind loan from a member and costs US $499.
Isn't this an attractive box or what? Makes you want to sit there and just play with all those sliders! Careful though as setting them all back to zero is very time consuming. Fortunately there is a bypass button. Connectivity is extensive in the back:
You can even use bare wire if you want!
Note: Harman owns dbx. Our company, Madrona Digital, buys some of their product lines but not these. Still, feel free to read any bias in my subjective remarks.
dbx 1231 Measurements
Let's start with EQ bypassed and input/output of 4 volts:
Distortion is at -105 dB which is very good for the class. Don't like the power supply noise but they are at -118 dB so we can ignore them. Turning on the EQ but keeping all the sliders at 0 shows the penalty of the full pipeline:
We are right at noise floor of 16 bit audio so not bad still. Here is our signal to noise ratio which is impacted the most:
Frequency response is flat in audible band with EQ bypassed:
It is hard to get rid of the channel mismatch due to notches in the gain control with the pot itself being fully variable. Repeatability is hard as well for the same reason.
I was pleased to see it handle up to 9 volts input before clipping:
IMD distortion is respectable with EQ bypassed and not too bad with it active:
Crosstalk is excellent either way: (better than most amplifiers)
I was disappointed to see a rise in distortion at low frequencies:
Conclusions
Good to see the word "professional" has a meaning here in delivering a low distortion and noise graphic EQ. My memories of consumer units was that they were hiss factories. Not so here. This is a quality piece with reasonable price to match it for analog lovers.
Note that in general, graphic equalizers are poor at dealing with room modes or speaker correction. You need parametric EQ for that. The dbx 1231 has a lot of bands so you may be able to get close with it but still not an optimal tool.
I am going to recommend dbx 1231 graphic eq if you need such a device.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Isn't this an attractive box or what? Makes you want to sit there and just play with all those sliders! Careful though as setting them all back to zero is very time consuming. Fortunately there is a bypass button. Connectivity is extensive in the back:
You can even use bare wire if you want!
Note: Harman owns dbx. Our company, Madrona Digital, buys some of their product lines but not these. Still, feel free to read any bias in my subjective remarks.
dbx 1231 Measurements
Let's start with EQ bypassed and input/output of 4 volts:
Distortion is at -105 dB which is very good for the class. Don't like the power supply noise but they are at -118 dB so we can ignore them. Turning on the EQ but keeping all the sliders at 0 shows the penalty of the full pipeline:
We are right at noise floor of 16 bit audio so not bad still. Here is our signal to noise ratio which is impacted the most:
Frequency response is flat in audible band with EQ bypassed:
It is hard to get rid of the channel mismatch due to notches in the gain control with the pot itself being fully variable. Repeatability is hard as well for the same reason.
I was pleased to see it handle up to 9 volts input before clipping:
IMD distortion is respectable with EQ bypassed and not too bad with it active:
Crosstalk is excellent either way: (better than most amplifiers)
I was disappointed to see a rise in distortion at low frequencies:
Conclusions
Good to see the word "professional" has a meaning here in delivering a low distortion and noise graphic EQ. My memories of consumer units was that they were hiss factories. Not so here. This is a quality piece with reasonable price to match it for analog lovers.
Note that in general, graphic equalizers are poor at dealing with room modes or speaker correction. You need parametric EQ for that. The dbx 1231 has a lot of bands so you may be able to get close with it but still not an optimal tool.
I am going to recommend dbx 1231 graphic eq if you need such a device.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
